Methods for reconstruction and maintenance of chimney necks

The use of chimney necks and offtake pipes, made of polymeric composite materials such as glass reinforced plastic is the comprehensive solution in increasing the life cycle of gas exhaust ducts at their reconstruction and maintenance. The use of envelope made of polymeric composite materials makes it possible to obtain jointless structures for offtake pipes and chimney necks, which are quickly and easily build, by the process of winding. Construction solutions are given. The transition from horizontal winding to the vertical one is suggested. It allows to omit the tilting operation of the envelope as well as to lower erecting loads. As a result material consumption of the envelope is decreased.